{
"$schema": "https://developer.microsoft.com/json-schemas/core-build/serve.schema.json",
"port": 4321,
"https": true,
"initialPage": "https://localhost:5432/workbench",
//you need to replace initialPage url with your sharepoint url
//Something like "initialPage": "https://<mysharepointurl>.sharepoint.com/sites/Mysite",
"api": {
"port": 5432,
"entryPath": "node_modules/@microsoft/sp-webpart-workbench/lib/api/"
}